Various types of oil cleaning sheets for makeup are well known, for wiping off oils which surface on different parts of the face, especially the nose, cheeks, forehead and eyebrows, to maintain a clean face and to facilitate application and spreading of cosmetics. When makeup is applied over oils which have surfaced on the face, the cosmetic material fails to properly adhere to the skin, thus impeding its spreading and preventing adequate performance of the effect of the makeup. An additional effect can be exhibited after makeup is applied, to prevent crumbling of the makeup or “oily appearance”, by using oil cleaning sheets to wipe off oils which constantly surface on the skin after application of makeup.
The most widely used type of oil cleaning sheets among the many kinds of oil cleaning sheets are those obtained by making paper from oil absorbing plant fibers such as hemp or synthetic pulp. Sheets made from these paper materials, however, while having high oil absorption, also have a disadvantage of high irritation to skin as a result of the hardness and surface roughness of the fiber materials used. In order to overcome this irritation to the skin, high-compression roller pressing is carried out during production of the oil cleaning sheets, or the surface of the paper may be coated with an inorganic powder such as calcium carbonate powder along with a sizing agent. However, in the former case there is again the disadvantage of skin irritation, because the fibers smashed by the roll pressing become raised over time, while in the latter case a disadvantage results in that the surface of the paper becomes covered with the sizing agent, unavoidably lowering the oil absorbing power.
Japanese Unexamined Utility Model Publication (Kokai) No. 4-45591 is aimed particularly at solving the problems caused by roll pressing during production of oil cleaning sheets and by coating of paper surfaces with inorganic powders such as calcium carbonate powder, and it teaches adhesion of porous globular beads onto the surface of oil cleaning sheets. According to this proposal, adhesion of porous globular beads onto the surface of oil cleaning sheets. According to this proposal, adhesion of porous globular beads provides an effect of allowing efficient absorption of skin oils.
Also, Japanese Unexamined Patent Publication (Kokai) No. 6-319664 teaches improvement in skin oil absorption by adding (B) an inorganic filler to (A) a raw pulp material composed mainly of plant fiber for preparation of a paper making material, to make sheets with a paper hardness of at least 0.7 (g/cm2).
The oil cleaning sheets produced by the methods taught in these publications are effective at reducing irritation to skin during their use. However, the improvement in skin oil absorption with these oil cleaning sheets is limited, and further improvement is therefore desired. These oil cleaning sheets also have an additional problem in that the state of oil absorption of skin oils, i.e. the wiping effect cannot be easily and accurately assessed during their use. The difficulty in assessing the wiping effect means that the user cannot achieve satisfaction by the removal of skin oils from the face. That is, from the point of view of the user, it is a very important evaluating factor to determine whether and how much skin oils have been removed from the face of the user when the oil cleaning sheets are used, and therefore satisfaction with makeup application varies greatly depending on this factor.
There also exist publicly known oil cleaning sheets for makeup which especially focus on allowing easy assessment of the wiping effect on skin oils, as discussed above. For example, Japanese Examined Patent Publication No. 56-8606 teaches an oil cleaning sheet for makeup which is characterized by mixture of hemp fibers with polyolefin resin fibers in an amount of 10–70% by weight and preparation of sheets with a density of 12–50 g/cm2. Because these oil cleaning sheets have a construction with transparent-like polyolefin fibers mixed with non-transparent hemp fibers, the hemp fibers which are non-transparent prior to use exhibit a transparent-like property upon absorption of oil, thus allowing the skin oil wiping effect to be clearly assessed.
In addition, Japanese Unexamined Utility Model Publication (Kokai) No, 5-18392 discloses oil cleaning sheets characterized in that inorganic or organic particulate bodies such as clay particles, fine silica particles, fiber powder or the like are added to oil cleaning paper to form a smooth side on the surface of the oil cleaning paper. Since these oil cleaning sheets contain particles in the gaps between the fibers of the oil cleaning paper, skin oils moisturize the entirety of the oil cleaning sheet while also filling the gaps between the paper fibers and the particles, providing an effect of rendering the oil cleaning paper even more transparent, i.e, giving the user a “satisfaction that skin oil has been removed”.
Nevertheless, although the 2 types of oil cleaning sheets mentioned above exhibit certain degrees of effects of transparency by oil absorption and assessment of oil absorption thereby, as a drawback they have a reduced amount of oil absorption which is the most important aspect for oil cleaning sheets, and it is difficult to achieve full transparency of the oil cleaning sheets upon oil absorption. Consequently, there still remains a demand for oil cleaning sheets with even greater oil absorption which can also be rendered transparent to give adequate satisfaction to users.
Another problem which is common to conventional oil cleaning sheets arises from the fact that they are made from paper types produced as thin paper from fiber materials, and thus they tend to be easily damaged when the user employs them to wipe skin oils from the face and must be immediately replaced. Because of the high cost of commercially available oil cleaning sheets, it is desireable to provide tougher oil cleaning sheets which do not need such immediate replacement.
In addition to the above problems, the prior art oil cleaning sheets suffer from another problem in the summer season and in an air-conditioned room under the highly increased temperature, because under such conditions, the oil cleaning sheets are insufficient to completely remove the sweat from the face surface. The unremoved sweat further causes insufficient compatibility and adhesion of the cosmetic material to the skin, because the sweat contains skin oil dissolved therein. It is therefore desired to provide an oil cleaning sheet having an excellent absorption capacity of liquid including sweat, in addition to excellent oil absorption capacity and other advantages.